Luciferase from Photinus pyralis is widely used in biotechnology and research as a reporter gene to study gene expression. It catalyzes the oxidation of luciferin, producing light, which allows for real-time monitoring of biological processes. This enzyme is essential in bioluminescence imaging, enabling non-invasive tracking of cellular activities, tumor growth, and gene regulation in living organisms. It is also utilized in drug discovery to assess the efficacy of compounds by measuring changes in light emission. Additionally, it plays a role in environmental monitoring, detecting microbial contamination in water and food samples. Its high sensitivity and specificity make it a valuable tool in molecular biology and diagnostics.